Traumatic Brain Injury and Gut Problems Connection

Traumatic Brain Injury, Leaky Gut, and Integrative Chiropractic Care: How the Brain–Gut Axis Breaks Down and How to Support Healing

Introduction: When a Head Injury Starts to Hurt the Gut

When most people think about a traumatic brain injury (TBI), they picture headaches, memory problems, dizziness, or balance issues. What many do not expect are stomach problems, such as nausea, constipation, diarrhea, or a sudden loss of appetite. But these gut issues are very common after a concussion or more serious TBI. Cognitive FX+1

Research indicates that a TBI can alter the functioning of the entire digestive system. The injury can:

• Increase intestinal permeability (often called “leaky gut”)

• Disrupt the gut microbiome (the trillions of bacteria that live in the intestines)

• Interfere with the enteric nervous system, the “second brain” in the gut

• Trigger long-term inflammation and immune activation

These changes can worsen the brain injury and slow recovery. They can also cause long-lasting digestive symptoms that make life miserable. PMC+2PMC+2

At the same time, the gut sends constant signals back to the brain through the brain–gut axis. When this two-way communication is disrupted, both the brain and gut can get stuck in a cycle of stress and inflammation. Integrative chiropractic care, particularly when combined with functional medicine, aims to support the brain–gut axis by enhancing nervous system function, restoring vagal tone, and reducing inflammation throughout the body. PMC+2jmsgr.tamhsc.edu+2

In this article, we will break down:

• How TBI damages the gut and creates leaky gut

• Why gut changes can worsen brain injury

• Common digestive symptoms after TBI

• How diet, lifestyle, and microbiome support help

• How integrative chiropractic care, including the clinical approach of Dr. Alexander Jimenez, DC, APRN, FNP-BC, may support brain–gut healing

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Understanding the Brain–Gut Axis After TBI

What Is the Brain–Gut Axis?

The brain–gut axis is the constant two-way communication network between:

• The brain and spinal cord (central nervous system)

• The enteric nervous system (the nerves inside the gut wall)

• The vagus nerve (major parasympathetic nerve running from the brainstem to the gut)

• The immune system

• The gut microbiome

Signals travel up and down this axis through nerves, hormones, immune chemicals, and bacterial metabolites. A healthy brain–gut axis helps control:

• Digestion and gut motility (how quickly food moves)

• Inflammation in the intestines and the brain

• Stress responses and mood

• Appetite and energy

After a TBI, this axis becomes disturbed. Studies show that brain injury can quickly lead to changes in gut permeability, microbiome balance, immune activation, and autonomic nervous system function (sympathetic and parasympathetic balance). PMC+2PMC+2

How TBI Shocks the Gut

TBI not only injures brain tissue. It also sets off a strong systemic inflammatory response that affects the gut. Animal and human studies show:

• Increased intestinal permeability (“leaky gut”)

• Damage to intestinal cells and tight junction proteins

• Bacterial movement (translocation) from the gut into the bloodstream

• Changes in gut motility and blood flow

This chain of events can lead to sepsis, multi-organ failure, and long-term inflammation if severe and untreated. PMC+2WJGnet+2

The result is that a brain injury quickly becomes a whole-body problem, with the intestinal tract playing a major role.

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Leaky Gut: How TBI Damages the Intestinal Barrier

What Is Intestinal Permeability?

Under healthy conditions, the cells lining the intestines form a tight barrier. They allow nutrients and water to pass through but block toxins, bacteria, and large food particles from entering the bloodstream.

Leaky gut (increased intestinal permeability) happens when this barrier becomes weak. The “tight junctions” between cells loosen, and the wall becomes more porous.

How TBI Causes Leaky Gut

Research in both animal models and human patients shows that TBI:

• Increases intestinal permeability within hours to days

• Alter proteins like ZO-1 and occludin that keep the barrier tight

• Allows bacteria and bacterial toxins (like LPS) to cross into the bloodstream

• Triggers systemic inflammation and can contribute to multi-organ failure in severe cases PMC+2UKnowledge+2

These changes are not just short-term. Some studies suggest that barrier problems and immune activation can persist long after the initial injury, perpetuating chronic inflammation and ongoing symptoms. PMC+1

Why Leaky Gut Matters for the Brain

When gut contents leak into the bloodstream, the immune system becomes highly activated. This leads to:

• High levels of inflammatory cytokines

• Oxidative stress

• Changes in blood–brain barrier integrity

These inflammatory signals and toxins can reach the brain, exacerbating the secondary phase of brain injury, which includes ongoing neuronal damage, microglial activation, and neurodegeneration. PMC+2BioMed Central+2

In other words, leaky gut can feed back into the brain, making the TBI worse or more chronic.

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Dysbiosis: How TBI Changes the Gut Microbiome

What Is Gut Dysbiosis?

Dysbiosis means an unhealthy shift in the composition and function of gut bacteria. Instead of a rich, diverse microbiome that supports digestion and immune health, the gut becomes dominated by fewer, less helpful, or even harmful species.

TBI-Induced Changes in Gut Bacteria

Several studies show that TBI can:

• Reduce overall microbial diversity

• Decrease beneficial bacteria

• Increase bacteria associated with inflammation

• Change the production of short-chain fatty acids and other metabolites PMC+2PMC+2

These bacterial changes are not just cosmetic. Dysbiosis can:

• Increase intestinal permeability

• Activate immune cells in the gut wall

• Produce metabolites that either calm or inflame the brain

• Affect mood, pain perception, and cognition

Some researchers even suggest using gut microbiome patterns as biomarkers to track the severity and recovery of TBI. PMC+1

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Enteric Nervous System and Motility: When the “Second Brain” Is Disturbed

The gut contains its own nervous system, called the enteric nervous system (ENS). It works with the vagus nerve and spinal cord to control:

• Muscle contractions of the intestines

• Secretion of digestive juices

• Blood flow to the gut

After a TBI, damage to the autonomic nervous system and brain–gut signaling can cause dysautonomia and dysmotility (abnormal movement of the gut). Cognitive FX+2PMC+2

Studies on the brain–gut axis dysfunction in TBI show that:

• Sympathetic “fight-or-flight” activity can stay too high

• Parasympathetic (vagal) activity can be too low

• The ENS may receive confusing or reduced input

• Motility can become too fast (diarrhea) or too slow (constipation) PMC+2BioMed Central+2

This helps explain why so many patients develop constipation, diarrhea, bloating, or stomach pain after head trauma.

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Common Digestive Symptoms After TBI

Many survivors are surprised when gut symptoms appear days, weeks, or even months after the injury. Clinical reports and rehab centers describe a wide range of post-TBI gastrointestinal problems, including:

• Nausea and vomiting

• Loss of appetite or early fullness

• Constipation or diarrhea

• Bloating and gas

• Reflux or heartburn

• Food intolerances or new sensitivities Cognitive FX+3Cognitive FX+3Flint Rehab+3

For some patients, these symptoms are related to:

• Direct changes in the  autonomic control of the gut

• Medications (like pain meds) that slow motility

• Changes in physical activity

• Hormonal and stress responses

• Inflammation and dysbiosis

Flint Rehab and other TBI recovery programs note that addressing gut health often helps alleviate brain symptoms as well, because the brain and gut are closely linked through the microbiome, immune system, and vagus nerve. neuropraxisrehab.com+3Flint Rehab+3Flint Rehab+3

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How Gut Problems Can Worsen Brain Injury

Systemic Inflammation and Neuroinflammation

As leaky gut and dysbiosis get worse, bacterial products and inflammatory molecules circulate through the bloodstream. These can:

• Activate immune cells in blood vessels and organs

• Increase blood–brain barrier permeability

• Trigger or maintain microglial activation in the brain

Reviews on the brain–gut axis in TBI show that chronic systemic inflammation is a major driver of long-term cognitive problems, mood changes, and neurodegeneration after head trauma. PMC+2PMC+2

Dysautonomia and Stress Responses

TBI can also disrupt the balance of the autonomic nervous system. Many patients develop dysautonomia, characterized by unstable heart rate, blood pressure, and gut motility. This can create:

• Poor blood flow to the intestines

• Abnormal motility (constipation or diarrhea)

• Worsening nausea with activity or position changes Cognitive FX+2jmsgr.tamhsc.edu+2

Because the vagus nerve carries signals both ways, low vagal tone can mean less calming input to the brain and weaker control of inflammation in the gut. This keeps the brain–gut axis locked in a state of stress and inflammation.

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Nutrition and Microbiome Support After TBI

Why Diet Matters for Brain–Gut Recovery

Diet is one of the most powerful tools for influencing gut bacteria, intestinal barrier function, and inflammation. Reviews on macronutrients, microbiota, and neuroinflammation in TBI show that certain dietary patterns can either fuel or calm brain and gut inflammation. MDPI+1

Key goals include:

• Reducing ultra-processed foods that are high in sugar, unhealthy fats, and additives

• Increasing fiber to feed beneficial bacteria

• Supporting the barrier with nutrients like glutamine, omega-3 fatty acids, and polyphenols

• Balancing blood sugar to support energy and brain healing

Helpful Food Choices

While each person’s needs are unique, many TBI recovery programs and functional clinicians recommend a pattern similar to a Mediterranean-style anti-inflammatory diet:

• Colorful fruits and vegetables (berries, leafy greens, cruciferous vegetables)

• Healthy fats (olive oil, avocado, nuts, seeds, omega-3-rich fish)

• Lean proteins (fish, poultry, eggs, beans, lentils)

• High-fiber foods (oats, quinoa, legumes, vegetables)

• Fermented foods, if tolerated (yogurt with live cultures, kefir, kimchi, sauerkraut)

These foods support microbial diversity, produce short-chain fatty acids like butyrate, and help repair both gut and brain tissues. Flint Rehab+2neuropraxisrehab.com+2

Probiotics and Targeted Supplements

Some papers suggest probiotics and other microbiome-directed therapies may help regulate the brain–gut axis, reduce inflammation, and improve outcomes after TBI, although research is still developing. PMC+2BioMed Central+2

Under the guidance of a healthcare provider, survivors may consider:

• Probiotic blends with evidence for gut barrier support

• Prebiotic fibers (in food or supplements)

• Omega-3 fatty acids

• Nutrients that support intestinal lining (like L-glutamine and zinc)

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Integrative Chiropractic Care and the Brain–Gut Connection

How Spinal Alignment and Nerve Function Affect the Gut

The nervous system controls every organ of the body, including the digestive tract. Misalignment or dysfunction in the spine may affect how nerve signals travel between the brain, spinal cord, and gut. Chiropractors and integrative clinicians argue that improving spinal function can help the nervous system communicate more clearly with the intestines and support the brain–gut axis. jmsgr.tamhsc.edu+2 El Paso, TX Doctor of Chiropractic+2

Key pathways include:

• Vagus nerve and upper cervical spine – The vagus nerve exits near the upper neck and brainstem. Restrictions or poor alignment in this area may affect vagal tone and parasympathetic activity, which are essential for digestion and controlling inflammation. PMC+1

• Thoracic and lumbar spinal segments – These regions carry sympathetic and parasympathetic fibers that control gut motility, secretion, and blood flow. Dysfunction may contribute to IBS-like symptoms, constipation, or diarrhea. PMC+1

By using spinal adjustments, soft-tissue work, and rehabilitative exercises, integrative chiropractic care aims to:

• Reduce mechanical stress on the nervous system

• Improve autonomic balance (better parasympathetic activity, calmer sympathetic tone)

• Support healthy motility and gut blood flow

• Help restore brain–gut communication

Chiropractic Care, TBI, and Gut Health in Practice

Articles aimed at the public explain that chiropractic care may help TBI survivors by:

• Improving joint and muscle function in the neck and spine

• Supporting better posture and blood flow

• Enhancing the body’s natural healing responses through improved nervous system function neuropraxisrehab.com+2jmsgr.tamhsc.edu+2

Some chiropractic and rehab clinics note that as spinal function improves and vagal tone rises, patients often report:

• Less nausea

• Better bowel regularity

• Less bloating and abdominal discomfort

• Better stress tolerance and sleep

While more high-quality clinical trials are needed, these observations align with what researchers are discovering about the role of the autonomic nervous system and microbiome in TBI recovery. PMC+2PMC+2

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Clinical Insights from Dr. Alexander Jimenez, DC, APRN, FNP-BC

Dr. Alexander Jimenez is a dual-scope doctor of chiropractic and board-certified nurse practitioner who focuses on integrative, functional, and injury-based care. In his clinical work with motor vehicle accident patients and TBI survivors, he frequently sees gut issues appear alongside brain symptoms. El Paso, TX Doctor Of Chiropractic+1

On his site, Dr. Jimenez describes how TBI and other trauma can:

• Disrupt gut bacteria and weaken the intestinal wall

• Trigger leaky gut and systemic inflammation

• Worsen fatigue, brain fog, and mood problems

• Slow down recovery from injuries and pain syndromes El Paso, TX, Doctor of Chiropractic+1

His Integrative Brain–Gut Approach

In practice, Dr. Jimenez often combines:

• Structural chiropractic care – Gentle spinal adjustments focused on restoring alignment and motion in the cervical, thoracic, and lumbar spine to improve nervous system function and vagal tone.

• Functional medicine evaluation – Detailed history, lab testing (when appropriate), and imaging to understand inflammation, gut barrier integrity, and microbial balance.

• Gut-focused nutrition and lifestyle plans – Anti-inflammatory diets, microbiome-supporting foods, hydration, sleep support, and stress management tailored to the patient’s injury and health status.

• Rehabilitation and movement – Graded exercise, postural training, and neuro-rehab strategies to support both brain and body.

By treating the brain, spine, and gut together, his clinical model recognizes that TBI recovery improves when the entire brain–gut axis is supported, not just the obvious head injury. El Paso, TX Doctor Of Chiropractic+1

Patients and professionals can learn more about his work and publications through his clinical site, DrAlexJimenez.com, and his LinkedIn profile. El Paso, TX Doctor Of Chiropractic+1

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Step-by-Step Brain–Gut Recovery Plan After TBI

This is general education, not personal medical advice. Always work with your own healthcare team.

1. Get a Proper Medical Evaluation

• Seek emergency care for any red-flag symptoms (severe headache, repeated vomiting, seizures, sudden weakness, confusion, or loss of consciousness).

• Work with a neurologist, sports medicine specialist, or a TBI clinic for imaging and diagnosis when necessary.

2. Track Digestive and Brain Symptoms Together

Keep a simple log of:

• Headache, dizziness, brain fog, and mood symptoms

• Nausea, constipation, diarrhea, bloating, and appetite

• Foods eaten, medications taken, and daily stress level

Patterns in this log can help your providers understand how your brain and gut are interacting. Flint Rehab+1

3. Shift Toward an Anti-Inflammatory, Gut-Supportive Diet

With your clinician’s guidance, consider:

• Filling half your plate with colorful fruits and vegetables

• Choosing whole grains and legumes over refined starches

• Using olive oil, nuts, and seeds as the main fat sources

• Including fish rich in omega-3s a few times per week

• Limiting sugary drinks, ultra-processed foods, and alcohol

This style of eating helps support gut bacteria, reduce inflammation, and fuel brain recovery. Flint Rehab+2neuropraxisrehab.com+2

4. Support the Microbiome and Barrier

Depending on your case, your healthcare team may suggest:

• Probiotics or fermented foods (if tolerated)

• Prebiotic fiber-rich foods like onions, garlic, leeks, asparagus, and oats

• Nutrients that support gut lining repair (e.g., glutamine and zinc)

• Adequate hydration throughout the day

These steps can help reduce leaky gut and calm systemic inflammation, which may in turn help brain symptoms. PMC+2PMC+2

5. Consider Integrative Chiropractic and Functional Care

Under the care of a qualified chiropractor and/or integrative team (such as a dual-scope provider like Dr. Jimenez), a TBI survivor may benefit from:

• Gentle spinal adjustments to improve alignment and nervous system function

• Techniques that support vagal tone (breathing, posture, cervical care)

• Individualized rehab exercises for balance, coordination, and posture

• Functional medicine strategies to address inflammation, hormones, and gut function

The goal is not to “cure” TBI with a single treatment, but to reduce the load on the nervous system, enhance brain–gut communication, and create the optimal environment for healing. neuropraxisrehab.com+2jmsgr.tamhsc.edu+2

6. Monitor Progress and Adjust Over Time

Recovery from TBI and gut disruption is often not a straight line. It may involve:

• Flare-ups occur when stress, infections, or poor sleep occur

• Changes in medication that affect motility or appetite

• Shifts in diet and lifestyle that need fine-tuning

Working closely with a clinical team that understands both TBI and gut health can help you adapt your plan and stay on track.

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Conclusion: Healing the Brain–Gut Axis After TBI

A traumatic brain injury does not only affect the brain. It also hits the gut hard, leading to leaky gut, dysbiosis, autonomic dysfunction, and a wave of inflammation that can loop back and worsen brain problems. Symptoms like nausea, constipation, diarrhea, and loss of appetite are not “in your head”—they are real signs that the brain–gut axis has been disrupted. PMC+3Cognitive FX+3Flint Rehab+3

The good news is that the brain–gut axis can be supported from many directions:

• Anti-inflammatory, microbiome-friendly nutrition

• Targeted supplements and lifestyle support

• Careful management of autonomic and motility issues

• Integrative chiropractic care that improves spinal alignment, vagal tone, and nervous system balance

Clinicians like Dr. Alexander Jimenez, DC, APRN, FNP-BC, show how combining chiropractic adjustments, functional medicine, and rehab can create a comprehensive plan that respects the deep connection between the brain, spine, and gut. El Paso, TX Doctor Of Chiropractic+1

With the right support, many TBI survivors can move from constant gut distress and brain fog toward better digestion, clearer thinking, and a more stable, resilient nervous system.

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